字符串操作 关键字高亮

将string字符串转换为array数组
NSArray *array = [Str componentsSeparatedByString:@","];

将array数组转换为string字符串
NSString *tempString = [mutableArray componentsJoinedByString:@","];--分隔符

//替换  如: 1234****5678
-(NSString *)changeTelePoneNumenber:(NSString*)str
{
 if (str  && ![str isEqualToString:@""]) {
        str = [str stringByReplacingCharactersInRange:NSMakeRange(3, 4) withString:@"****"];
    }
   return str;
}
//将123 从 123456中  替换或删除
        NSString *str1 = @"123456";
        NSString *str2 = @"123";
        string = [str1 stringByReplacingOccurrencesOfString:str2 withString:@""];
        NSLog(@"~~~~ =%@", str1);//456

//判断str 是否包含有 qwe
NSString *str = @"qwer";
           if([Label.text rangeOfString:@"qwe"].location != NSNotFound) {
       NSLog(@"yes");
    } else{
       NSLog(@"no");
    }

//在指定下标插入字符串
NSMutableString *str1=[[NSMutableStringalloc]initWithString:@"hello"];//存在堆区，可变字符串
    [str1 insertString:@"str" atIndex:3];       
  
// 删除范围内的字符串
// - (void)deleteCharactersInRange:(NSRange)range;
       
// 拼接字符串
// stringByAppendingString

类型转换
NSString *tempA = @"123";
NSString *tempB = @"456";

// 1，字符串拼接
NSString *newString = [NSString stringWithFormat:@"%@%@",tempA,tempB];

//2，字符转NSInteger      NSInteger k = [newString integerValue];

//2，NSInteger转字符      NSString *s = [NSString stringWithFormat:@"%ld",k];

//2，字符转int                int intString = [newString intValue];

//3，int转字符                NSString *stringInt = [NSString stringWithFormat:@"%d",intString];

//4，字符转float             float floatString = [newString floatValue];

//5，float转字符            NSString *stringFloat = [NSString stringWithFormat:@"%f",intString];

NSNumber怎么转换成NSString
或者
NSNumber *
NSString *String = number.description;

#pragma mark - 比较字符串
NSString *str1 = @"basb";
NSString *str2 = @"adfsd";
BOOL result = [str1 compare:str2];
NSLog(@"比较结果==%d", result);
返回值：
typedef enum _NSComparisonResult {     NSOrderedAscending = -1,    // < 升序
     NSOrderedSame,              // = 等于
     NSOrderedDescending   // > 降序
} NSComparisonResult;


例子：版本号比较
    NSString *num1 = @"5.2.0";
    NSString *num2 = @"5.3.0";
 
    if ([num1 compare:num2 options:NSNumericSearch] == NSOrderedDescending)
    {
        ULog(@"%@ is bigger",num1);
    }else {
        ULog(@"%@ is bigger",num2);
    }
解释：
NSOrderedDescending是降序，如果numb1>numb2用这个函数相比较那么就等于降序。


#pragma mark - 获取字符串
截取字符串
        NSString *str1 = @"123456qwer";
 // 1//第几位到最后一位
        NSString *str2 = [str1 substringFromIndex:1];
        NSLog(@"%@", str2);//23456qwer
// 1//第0位(开始)到  哪一位
NSString *str3 = [str1 substringToIndex:3];
        NSLog(@"%@", str3);//123
 // 2
NSString *str1 = @"1234567";
        NSRange range = NSMakeRange(2, 3);
        NSString *str4 = [str1 substringWithRange:range];
        NSLog(@"%@", str4);//345   打印

#pragma mark - 以某个字符开头或者结尾
        NSString *str1 = @“12345";
   // 判断字符串是否以什么字符开头
        if ([str1 hasPrefix:@“45"]) {  
             NSLog(@"有");
        }else{
           NSLog(@"无");
        }
   // 判断字符串是否以什么字符后缀
        if ([str1 hasSuffix:@“12"]) {
           NSLog(@"有");
        }else{
           NSLog(@"无");
        }

#pragma mark - 大小写更换
        NSString *str = @"BBBBfdfdsds";
        // 大写变小写
        str = [str uppercaseString];
        // 小写变大写
        str = [str lowercaseString];
        NSLog(@"%@", str);


////邮箱
+ (BOOL) validateEmail:(NSString *)email
{
    NSString *emailRegex = @"[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,4}";
    NSPredicate *emailTest = [NSPredicate predicateWithFormat:@"SELF MATCHES %@", emailRegex];
    return [emailTest evaluateWithObject:email];
}

//判断字符串是否为纯数字
-(BOOL)ispureInt:(NSString*)string
{
 NSScanner *scan = [NSScanner scannerWithString:string];
   int  val;
   return [scan scanInt:&val]&&[scan isAtEnd];
}
判断字符串是否为纯数字
明杰//MJExtension.h
if ([self. phoneTxetField.text  mj_isPureInt]) {
           
        }

 // 给数组 排序
[self.allKeysArray sortUsingSelector:@selector(compare:)];

//
-(NSString *)textFieldText:(NSString *)text Str:(NSString*)str
{
   if ([text isEqualToString:@""]) {
       return @"";
    }
   if (![str isEqualToString:@""]) {
       return [NSString stringWithFormat:@"%@%@", text, str];
    }else{      
//根据起始位置和范围获得字符串(包括起始位置)      
 NSRange range = NSMakeRange(0, str.length - 1);
 NSString *string = [str substringWithRange:range];
       return string;
    }
}


http://www.jianshu.com/p/0180c4a765e5  正则   
https://www.zhihu.com/question/20350598  键盘类型

@"[a-zA-Z0-9]*"        0-9 a-z A-Z       个人认为 * 是可以删除  不然输入了之后无法删除 
@"[a-zA-Z0-9@.]*"      0-9 a-z A-Z @ .      个人认为 * 是可以删除  不然输入了之后无法删除
@"[\u4e00-\u9fa5]+"    中文
//输入的是中文    
- (BOOL)inputShouldChinese:(NSString*)string
{
    NSString *regex = @"[\u4e00-\u9fa5]+”;//中文
    NSPredicate *pred = [NSPredicate predicateWithFormat:@"SELF MATCHES %@",regex];
    if ([pred evaluateWithObject:string]) {
        return YES;
    }
    return NO;
}

//判断 整数 小数(两位小数) 格式
- (BOOL)textField:(UITextField *)textField shouldChangeCharactersInRange:(NSRange)range replacementString:(NSString*)string
{
   BOOL isHaveDian = YES;
    
if ([textField.text rangeOfString:@"."].location == NSNotFound){
        isHaveDian =NO;
    }
   if ([string length] > 0){
       unichar single = [string characterAtIndex:0];//当前输入的字符

       if ((single >= '0' && single <= '9') || single == '.'){//数据格式正确

           //首字母不能为0和小数点

           if([textField.text length] == 0){
               if(single == '.'){
                    [[HudManager manager] showHudWithText:@"亲，第一个数字不能为小数点!"];
                    [textField.text stringByReplacingCharactersInRange:range withString:@""];
                   return NO;
                }
               if (single == '0'){
                    [[HudManager manager] showHudWithText:@"亲，第一个数字不能为小数点!"];
                    [textField.text stringByReplacingCharactersInRange:range withString:@""];
                   return NO;
                }
            }
            
//输入的字符是否是小数点
           if (single == '.'){
               if(!isHaveDian){//text中还没有小数点
                    isHaveDian =YES;
                   return YES;
                }else{
                    [[HudManager manager] showHudWithText:@"亲，您已经输入过小数点了!"];
                    [textField.text stringByReplacingCharactersInRange:range withString:@""];
                   return NO;
                }
            }else{
               if (isHaveDian) {//存在小数点
                  //判断小数点的位数
                   NSRange ran = [textField.text rangeOfString:@"."];
                   if (range.location - ran.location <= 2) {
                       return YES;
                    }else{
                        [[HudManager manager] showHudWithText:@"亲，您最多输入两位小数!"];
                       return NO;
                    }
                }else{
                   return YES;
                }
            }
        }else{//输入的数据格式不正确
            [[HudManager manager] showHudWithText:@"亲，您输入的格式不正确!"];
            [textField.text stringByReplacingCharactersInRange:range withString:@""];
           return NO;
        }
    }else{
       return YES;
    }
}

字典转json字符串
NSData *data=[NSJSONSerialization dataWithJSONObject:dic options:NSJSONWritingPrettyPrinted error:nil];
获取的json字符
    NSString *jsonStr=[[NSString alloc]initWithData:data encoding:NSUTF8StringEncoding];
json字符串转字典
NSData *jsonData = [str dataUsingEncoding:NSUTF8StringEncoding];
    NSError *err;
    NSDictionary *dic = [NSJSONSerialization JSONObjectWithData:jsonData options:NSJSONReadingMutableContainers error:&err];
    if(err) {
        NSLog(@"json解析失败：%@",err);
    }
    NSLog(@"dic----%@", dic);
    for (NSString *key in dic) {
        NSLog(@"key===%@", key);
        NSLog(@"value===%@", dic[key]);
    }

//根据字符串生成类class
[vc isKindOfClass:[NSClassFromString(@"AProductSearchViewController") class]]

label.attributedText = [self changeTextColcrWithTitleStr:@"姓名*:" Str:@"*"];

-(NSAttributedString *)changeTextColcrWithTitleStr:(NSString *)title Str:(NSString *)str
{
    // 设置标签文字
    NSMutableAttributedString *attrituteString = [[NSMutableAttributedString alloc] initWithString: title];
   
    // 获取标红的位置和长度
    NSRange range = [title rangeOfString:str]; //获取需要变量文字的文字
   
    // 设置标签文字的属性
    [attrituteString setAttributes:@{NSForegroundColorAttributeName : [UIColor  redColor],   NSFontAttributeName : [UIFont systemFontOfSize:20.0]} range:range];
   
 //    titleLable.attributedText = attrituteString;
    return attrituteString;
}